The comment at the top of d/rules doesn't make sense. Please remove it.
debian/docs is empty. Just remove it.
Why "Priority: extra"?

The upstream makefile hides compilation commands. Please patch it not to
do that.

The program is built without debugging information. This is violation of
a "should" policy (§10.1).

The program is built with -O3 optimization even when
DEB_BUILD_OPTIONS=noopt is used.

You recommend tsclient, but this package has been removed form unstable
(see bug #547314).

Does anybody uses telnet these days? I think recommending it is
overkill, maybe Suggests would be more appropriate.

What is perl-base recommendation for? Essential packages in Recommends
looks a bit suspicious.

Lintian complains:
W: quickrdp source: out-of-date-standards-version 3.8.4 (current is 3.9.2)
E: quickrdp: helper-templates-in-copyright
I: quickrdp: hyphen-used-as-minus-sign usr/share/man/man1/quickrdp.1.gz:46
I: quickrdp: hyphen-used-as-minus-sign usr/share/man/man1/quickrdp.1.gz:50
There are some warnings from dpkg-shlibdeps:
dpkg-shlibdeps: warning: dependency on libwx_gtk2u_aui-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
dpkg-shlibdeps: warning: dependency on libwx_gtk2u_richtext-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
dpkg-shlibdeps: warning: dependency on libwx_gtk2u_html-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
dpkg-shlibdeps: warning: dependency on libwx_baseu_xml-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
dpkg-shlibdeps: warning: dependency on libwx_gtk2u_qa-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
dpkg-shlibdeps: warning: dependency on libwx_gtk2u_xrc-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
dpkg-shlibdeps: warning: dependency on libwx_baseu_net-2.8.so.0 could be avoided if "debian/quickrdp/usr/bin/quickrdp" were not uselessly linked against it (they use none of its symbols).
--
Jakub Wilk